<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>03JS的数据类型</title>
</head>
<body>
<!--JS数据类型分为原始类型和引用类型-->
<!--基本类型有number，string，boolean，null，undefined-->
<script>
  var a=1;
  let b=9.9;
  console.log(typeof a,typeof b);

  let c = 'GoodAfternoon';
  let d = 'Ameda';
  console.log(typeof c,typeof d);

  let e=true;
  let f=false;
  console.log(typeof e,typeof f);

  let g;
  console.log(g,typeof g)

  let obj={
    name:'张三',
    age:18
  };
  console.log(obj);
  console.log(obj.age,obj.name)

  obj.age=19;
  console.log(obj.age,obj);

  obj.like = '吃冰棍';
  console.log(obj);

  console.log(obj.eat);

  let arr = ['理亏','六倍','长肥',1,2.5,false];
  console.log(arr[1]);
  console.log(arr[90]);
</script>
</body>
</html>